This invention relates to a lubrication system, and more particularly, the invention relates to a valve used for scavenging lubricating fluid from separate compartments of a machine.
Gas turbine engines and other rotating machines typically have several bearing areas that must be lubricated and scavenged. On complex multi-shaft engines the number of individual bearing compartments can be as high as ten or more. Each bearing cavity must be scavenged separately to ensure that spent bearing oil is properly returned to the tank for reuse and not allowed to leak in the gas path of the engine where it may ignite.
A pump is used to scavenge the bearing cavities to remove the bearing oil. In the prior art, scavenging is typically accomplished by using separate scavenge pump elements for each compartment. That is, each bearing compartment has its own set of pump elements such that for complex multi-shaft engines there may be as many as ten or more sets of pump elements. This leads to a scavenge pump which is overly long and complex requiring many bearings, shafts, seals, and couplings. Therefore, what is needed is an improved lubrication system that scavenges each of the bearing compartments without using separate pump elements.